ASTM D6072-2008 809 Standard Practice for Obtaining Samples of Geosynthetic Clay Liners.pdf

1、Designation: D 6072 08Standard Practice forObtaining Samples of Geosynthetic Clay Liners1This standard is issued under the fixed designation D 6072; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe

2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers procedures for sampling geosyn-thetic clay liners (GCLs) for the purpose of laboratory testing.These procedures are des

3、igned to ensure that representativesamples are obtained and properly packaged for submittal to atesting laboratory.1.2 The procedures in this practice may be applied to eithersamples of unhydrated GCLs obtained at the project site priorto installation (or at the production facility, prior to shipmen

4、t tothe project site) or samples exhumed from a project site afterinstallation.1.3 It is assumed that the number of samples to be obtainedhas already been determined in the project specification,standard test method, or by prior agreement between thepurchaser and seller. This practice covers only th

5、e methods forobtaining a pre-arranged number of samples and does notdescribe methods for obtaining individual specimens from thesample.1.4 The values stated in SI units are to be regarded as thestandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with

6、its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 4220 Practices for Preserving and Transporting SoilSamplesD 4354 Pr

7、actice for Sampling of Geosynthetics for TestingD 4439 Terminology for GeosyntheticsD 5888 Guide for Storage and Handling of GeosyntheticClay Liners3. Terminology3.1 Definitions:3.1.1 geosynthetic clay liner (GCL), na manufacturedhydraulic barrier consisting of clay bonded to a layer or layersof geo

8、synthetics.3.1.2 sample, na portion of a material which is taken fortesting or for record purposes (See Practice D 4354).3.1.3 specimen, na specific portion of a material orlaboratory sample upon which a test is performed or which istaken for that purpose (See Practice D 4354).3.1.4 For definitions

9、of other geosynthetic terms used in thispractice, refer to Terminology D 4439.4. Significance and Use4.1 This practice provides a procedure by which samples ofGCL should be obtained for laboratory testing. The practiceapplies to materials obtained prior to installation (either at a jobsite or at a p

10、roduction facility) or exhumed material afterinstallation.4.2 Only GCL samples obtained in accordance with 5.1 ofthis practice will be considered representative of the actualmanufactured GCL for quality assurance/quality control (QA/QC) purposes4.3 The quantity of GCL received by the laboratory shou

11、ldbe sufficient for the preparation of several representative testspecimens for the standardized physical, hydraulic, and me-chanical tests to be performed on the GCLs.4.4 The procedures in this practice should be used by plantand field personnel for obtaining GCL samples for laboratorytesting.5. Pr

12、ocedure5.1 Obtaining Samples prior to Installation:5.1.1 In accordance with the project specifications or withPractice D 4354, divide the shipment or other given quantity ofGCL into lots, and select lot and laboratory samples. This willusually involve the selection of a certain number of finishedGCL

13、 rolls from which samples will be cut.1This practice is under the jurisdiction of ASTM CommitteeD35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.04 on GeosyntheticClay Liners.Current edition approved July 1, 2008. Published September 2008. Originallyapproved in 1996. Last p

14、revious edition approved in 2002 as D 607296(2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright

15、 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.2 Affix on the packaging of the GCL rolls to be sampledadhesive labels or other markings which clearly identify thatthe roll is to be sampled.5.1.3 Record the label information from each roll

16、 to besampled for future incorporation into within the qualityassurance/quality control (QA/QC) documentation for theGCL.5.1.4 Segregate the rolls identified for sampling. Refer toGuide D 5888 for the proper equipment and techniques forhandling the GCL rolls.5.1.5 Inspect the packaging of the select

17、ed GCL rolls fordamage. Describe and record the damage, if any.5.1.6 Remove the outer packaging from the GCL as care-fully as possible, taking precautions not to damage the GCLand to preserve the packaging as much as possible for re-useafter sampling is completed.5.1.7 Obtain samples from the select

18、ed GCL rolls. Thesurface on which the GCL is cut shall be smooth, hard, and freeof irregularities and potential contaminants. All samples shallbe obtained by cutting across the full width of the roll end,perpendicular to the edges. Samples shall be cut with a sharputility knife or other implement ca

19、pable of making a clean,straight cut through all components of the GCL. Unlessotherwise specified, the cut shall be made at a point that is 1.0m from the exposed end of the roll.NOTE 1At the discretion of the engineer, shorter or narrower samples,or both, may be obtained provided that the packaging

20、procedures in thisguide are followed.5.1.8 A unique sample number shall be written on thesample. Additional markings should be made on the sample toidentify the machine direction and the top/bottom sides of theGCL.5.1.9 The GCL sample shall then be manually rolled arounda core at least 75 mm in diam

21、eter, in the same direction as thecut. Care should be taken to wind the GCL without slack. Widestrapping tape (50 mm) shall then be wound around the samplein at least two places to secure the loose end. Bentonite lossfrom the sample may be minimized by applying the tapearound the roll ends.5.1.10 At

22、 least two layers of plastic sheeting shall be used towrap the GCL sample roll for shipment to the laboratory, so asto minimize GCL sample disturbance or changes in moisturecontent. A thin cellophane material may be used for the innerwrapping, provided it is wound securely and repeatedly aroundthe r

23、olled sample. The outer sheeting shall be at least 0.15 mm(6 mils) in thickness and shall be wrapped to minimize theamount of GCL shifting within the wrapping.5.1.11 To ensure proper sample chain-of-custody tracking,all shipping documents shall indicate the sample number,project name and contact, an

24、d laboratory name and contact.5.1.12 If an additional sample from the same GCL roll isrequired for testing, 5.1.6 through 5.1.10 of this practice maybe repeated on the exposed end of the roll until a sufficientamount of GCL is obtained.NOTE 2Additional material cut from the same roll is still consid

25、eredpart of the same sample therefore should not be designated any differentlythan those samples previously obtained from the same roll.5.1.13 Samples should be transmitted to the laboratory in amanner that minimizes the amount elapsed time, samplehandling, disturbances (such as moisture, vibration,

26、 impact,etc.) that could occur in transit. Expedited delivery will help toensure that moisture content changes are minimized.NOTE 3These packaging procedures were developed under the as-sumption that the area from which specimens are obtained is at least 75mm from the edges of the sample.5.2 Exhumin

27、g Samples after Installation:5.2.1 There are two methods for exhuming GCL samples.Method A is the suggested method for multi-component GCLsor GCLs covered with a geomembrane. Method B is thesuggested method when there is no multi-component GCL noris the GCL covered with a geomembrane, although Metho

28、d Acan be used in cases where larger samples are required.5.2.2 Method A Hand Cutting method.5.2.2.1 Using a small backhoe or other piece of constructionequipment carefully excavate a hole at the desired locationdown to within hand shoveling distance of approximately 150mm (6 in.) of the GCL. Once c

29、over removal begins, machineryshould not be placed in the area to be exhumed. To minimizestress on GCL, within 150 mm (6 in.) the GCL, the overlyingsoil should be removed by hand and any overlying geosynthet-ics shall be cut by hand. Measure the depth of the cover soil,as well, the inclination and d

30、irection of inclination; e.g., south,east, west, north.NOTE 4Once the overlying soil is removed, evaporation of water inthe GCL may occur. Consequently, the GCL should be removed no morethan 30 minutes from the time the overlying soil is removed. When a GCLis overlain by a geomembrane, the geomembra

31、ne should remain in placeuntil the GCL is to be sampled. If heating of the geomembrane by solarradiation is a concern during this period, a white fabric or white plasticsheet should be draped over the geomembrane to reflect solar radiation.5.2.2.2 The sample area shall be large enough such thatspeci

32、mens subsequently cut from the removed sample in thelaboratory for testing are no closer than 75 mm from any edge.The sample also must not be cut too close to the side of theexcavation so that the geomembrane and GCL may be repairedor patched as recommended by the manufacturers.5.2.2.3 If the GCL is

33、 overlain with a geomembrane, first thegeomembrane shall be cut over an area larger than thesubsequent GCL sample area and removed prior to cutting theGCL. GCL samples shall be cut with a sharp utility knife orother implement capable of making a clean, straight cutthrough all the components of the G

34、CL.5.2.2.4 The sample width and length dimensions shall bemeasured and recorded.5.2.2.5 To minimize the potential for bending or distortingthe GCL, the sample shall be kept flat at all times duringremoval and placed upon a nonporous rigid plate. This can beaccomplished by cutting a notch into the su

35、bgrade adjacent tothe GCL, placing the rigid plat into the notch adjacent to theGCL sample and either sliding the GCL onto the plate orsliding the plate below the GCL (see Fig. 1).5.2.2.6 To minimize changes in moisture content, at leasttwo layers of plastic sheeting shall be used to wrap the GCLsam

36、ple and plate for shipment to the laboratory, A thincellophane material may be used for the inner wrapping,D6072082provided the cellophane is wound securely and repeatedlyaround the sample and plate. The outer sheeting shall be at least0.1 mm (4 mils) in thickness and shall be wrapped tight enoughto

37、 minimize the amount of GCL shifting within the wrapping.5.2.2.7 Unique sample identification shall be marked on thewrapped sample.5.2.2.8 If requested and practical, a confining pressure canbe applied upon the GCL sample. This can be accomplishedeither by placing a second rigid plate over the GCL p

38、rior towrapping and then placing dead weights over the sample, or byplacing the sample in a container and then carefully placing asufficient amount of soil over the sample.5.2.2.9 Sample soils immediately adjacent to the GCL perPractices D 4220.5.2.2.10 If required, repair and/or patch the geosynthe

39、tics inthe excavation as recommended by the manufacturers andbackfill the entire excavation according to the protocol agreedto by the parties involved.5.2.2.11 To ensure proper sample chain-of-custody tracking,all shipping documents shall indicate the sample number,project name and contact, and labo

40、ratory name and contact.5.2.2.12 Samples should be transmitted to the laboratory ina manner that minimizes the amount of elapsed time, samplehandling, disturbances (such as moisture loss, distortion, im-pact, etc.) that could occur in transit. Expedited delivery willhelp to ensure that moisture cont

41、ent changes are minimized.5.2.2.13 Samples should be stored and handled by thelaboratory in a manner that minimizes the amount of elapsedtime, sample handling, disturbances (such as moisture loss,distortion, impact, etc.) that could occur prior to testing.5.2.3 3 Method B Coring Method5.2.3.1 Using

42、a small backhoe or other piece of constructionequipment carefully excavate a hole at the desired locationdown to within hand shoveling distance of approximately 15cm (6 in.) of the GCL. Carefully remove the remaining soil byhand to within 25 mm (1 in.) of the top of the GCL.5.2.3.2 Advance a hand au

43、ger with a 150 mm (6 in.)diameter, end-sharpened thin-wall sampling tube (see Fig.2(a) into the cover soil to the top of the GCL.NOTE 5Par Aide Turf Mender Model #1004 with Par Aide TubeBlade Model #1010 has been found satisfactory for this purpose.5.2.3.3 After advancing the auger to the surface of

44、 the GCL,a utility knife should be used to pre-cut the GCL around the150 mm (6 in.) diameter inner perimeter of the tube. Thenadvance the auger through the pre-cut GCL and approximately25 mm (1 in.) beneath the GCL.FIG. 1 (a) Digging Notch in Subgrade Adjacent to Sample Covered by Rigid Plate (b) Ri

45、gid Plate Placed into Notch Adjacent to GCLSample. (c) GCL sample on Rigid Plate.FIG. 2 (a) Auger and Sampling Tube Next to Spare SamplingTube Turned on its Side (b) Composite (Soil/GCL/Soil) SampleExtracted from Sampling Tube.D60720835.2.3.4 Withdraw the sampler from the soil formation ascarefully

46、as possible in order to minimize disturbance of thesample. The tube can be slowly rotated to shear the material atthe end of the tube, and to relieve water and/or suctionpressures and improve recovery. Retrieve the auger with itssoil/GCL/soil sample. Remove the thin-wall sampling tube atthe end of t

47、he auger, and immediately seal both sample endsassuring that the sample has no way of moving about in thetube.NOTE 6If soil is lost and not flush with either end of the tube, thenspacers or appropriate packing materials should be inserted prior tosealing the tube end(s) to provide proper confining p

48、ressure. Packingmaterials must be nonabsorbent and must maintain their properties toprovide the same degree of sample support with time.5.2.3.5 Unique sample identification shall be marked on theassembly, as well as, field orientation (i.e., top, bottom).5.2.3.6 If repair of the excavation area is r

49、equired, firstcarefully fill and compact the hole up to the level of the GCLwith soil. Then patch the sampled GCL hole with a patch ofsimilar GCL that is at least 0.3 m (12 in.) beyond the edges ofthe sampled hole placing 0.4 kg/m (0.25 lb/linear foot) ofbentonite between the patch and the GCL. Carefully backfillthe entire excavation according to the protocol agreed to by theparties involved.5.2.3.7 To ensure proper sample chain-of-custody tracking,all shipping documents shall indicate the sample number,project name and contact, and laboratory name and contact.5.2.3.8 S